Influence of fractional flow reserve on grafts patency. Systematic review and patient-level meta-analysis

Objective: To investigate the impact of invasive functional guidance for coronary artery bypass graft surgery (CABG) on graft failure. Background: Data on the impact of fractional flow reserve (FFR) in guiding CABG are still limited. Methods: Systematic review and individual patient data meta-analysis were performed. Primary objective was the risk of graft failure, stratified by FFR. Risk estimates are reported as odds ratios (ORs) derived from the aggregated data using random-effects models. Individual patient data were analyzed using mixed effect model to assess relationship between FFR and graft failure. This meta-analysis is registered in PROSPERO (CRD42020180444). Results: Four prospective studies comprising 503 patients referred for CABG, with 1471 coronaries, assessed by FFR were included. Graft status was available for 1039 conduits at median of 12.0 [IQR 6.6; 12.0] months. Risk of graft failure was higher in vessels with preserved FFR (OR 5.74, 95% CI 1.71–19.29). Every 0.10 FFR units decrease in the coronaries was associated with 56% risk reduction of graft failure (OR 0.44, 95% CI 0.34 to 0.59). FFR cut-off to predict graft failure was 0.79. Conclusion: Surgical grafting of coronaries with functionally nonsignificant stenoses was associated with higher risk of graft failure.